Some airfields do not include a control tower or are used relatively infrequently. At such airfields, it may not be economical to keep various aerodrome lighting energized nor to provide personnel to energize and de-energize the various aerodrome lighting. As a result, a system was devised that enables pilots to controllably energize the lighting at these airfields. This system, which may be referred to as Pilot Controlled Lighting (PCL), Pilot Activated Lighting (PAL), or more generally as Aircraft Radio Control of Aerodrome Lighting (ARCAL), allows aircraft pilots to control various aerodrome lighting using the aircraft communications radio. The PCL controlled aerodrome lighting may include one or more of the approach lights, runway edge lights, and taxiway lights.
To activate PCL aerodrome lights, an aircraft pilot tunes the radio to the specific PCL frequency associated with the aerodrome of interest, and then repeatedly operates (or “keys”) the radio microphone transmit switch a specific number of times within a specific time period. The specific number of clicks and the specific time period will depend upon the type of PCL system implemented at the airfield. Presently, there are two type of PCL systems—a type J system and a type K system. With type J systems, aerodrome lighting is energized by keying the radio microphone transmit switch 5 times within 5 seconds. With type K systems, aerodrome lighting is initially energized by keying the radio microphone transmit switch 7 times within 5 seconds. Thereafter, the intensity of the aerodrome lights in type K systems may be set to low, medium, or high intensity by keying the radio microphone transmit switch 3, 5, or 7 times, respectively, within 5 seconds. If runway identification lights are also controlled by a type K system, these lights may be turned off by keying the radio microphone transmit switch 3 times.
With both the type J system and the type K system, a 15-minute countdown commences upon energizing the aerodrome lighting. When the 15-minute countdown is completed, the aerodrome lighting is automatically deenergized. Whenever the aerodrome lighting is energized, each time a lighting command is issued, the 15-minute countdown is reset. At some airfields, the aerodrome lighting may flash once to warn a pilot that the aerodrome lighting will be deenergized within two minutes. It may thus be appreciated that aircraft pilots are encouraged to issue a fresh lighting command upon final approach to an PCL controlled aerodrome, even if the aerodrome lighting is energized. This ensures the aerodrome lighting is not deenergized at any point during the aircraft approach and landing phase.
The approach and landing phase of an aircraft is a relatively important phase of flight. When conducting an approach and landing, the primary focus of a pilot is preferably on such tasks as looking out for other traffic and communicating position, intent, etc. on the communication radio. However, when conducting an approach and landing at an PCL controlled aerodrome, the pilot may become focused on ensuring the aerodrome lighting gets energized and, once energized, stays energized. For example, the pilot may become focused on tuning the communication radio to the correct frequency, determining number of times to key the radio microphone transmit switch, and then keying the radio microphone switch the required number of times. Moreover, after energizing the aerodrome lighting, the pilot may issue one or more additional lighting commands to make ensure the aerodrome lighting remains energized throughout the approach and landing phase.
Hence, there is a need for a system to activate PCL controlled aerodrome lighting that does not rely on a pilot keying the radio microphone transmit switch in a defined manner and/or re-keying the radio microphone transmit switch in the same defined manner during an approach and landing phase to ensure aerodrome lighting remains energized. The present invention addresses at least these needs.